This invention relates to a numerical control device which is capable of controlling a machine tool having a large number of controlled axes, or a machine tool having two heads, by providing a plurality of standard numerical control devices each having data and numerical control processing capability using the arithmetic functions of their processors, one of the devices being a master device and the others being slave devices, and by connecting the master device to the slave devices through coupling circuits having a data exchange capability.
The numerical control of a machine tool which is required to be controlled in a complex manner, such as a machine tool having a large number of controlled axes or a lathe having two heads, is difficult to realize with a standard, mass-produced numerical control device because of its limited processing capability. Such control requires the use of a special-purpose numerical control device designed for a higher processing capability. The conventional special-purpose numerical control device of this kind, however, is designed and developed apart from standard numerical control devices and includes its own unique hardware and software. Production capacity therefore is small in scale so that the unit cost per device is quite high. Another disadvantage is that considerable time is required for delivery.